Hello, firstly, it was never stated in the Don's orders that you were killed because of your race. The reasoning given was that you had expressed interest in leaving the family and had sided with the opposing faction during the coup that was taking place.
While you may have genuinely been negotiating for permission to leave, this is the mafia. Deception and betrayal are part of that roleplay, and they are allowed to lie about their intentions. In this case, you approached them about leaving, they led you to believe it was possible, and ultimately decided to kill you instead.
The following excerpt from the PK guidelines outlines just this:
"CAUTION: This is the MAFIA, the don can LIE to you about having permission to leave, they can tell you you may leave, lowering your guard, and once you do, have you killed for leaving the faction. They have the same 2 weeks left orders timer to do so. "They gave me permission to leave but I didn't leave and they still pk'ed me" This falls under don's orders and by requesting to leave you demonstrated to the Don you are not committed to the faction, thereby giving him valid reason and suspicion to place don's orders against you."